Humidity

[Robert Harris]

Just a wild ass guess.  Since you are running an air cooled M/C, humid air 
carries heat away much better than dry air.  Bet your engine is running far 
cooler everywhere from the intakes,  heads, cylinders, etc. right out the 
pipes.  This change in the heat conduction of cooling air would be far more 
apparent and beneficial on an air cooled engine rather than a liquid cooled 
engine where the cooling jacket temp is far lower and much better regulated.

If the first ingredient ain't Habanero, then the rest don't matter.
Other Obsessions: Ferro-Equinary , 1972 "Killer Whale" Mustang
Robert Harris <bob at bobthecomputerguy.com>


-----Original Message-----
From:	Tom Cloud [SMTP:cloud at peaches.ph.utexas.edu]
Sent:	Tuesday, September 23, 1997 3:04 PM
To:	diy_efi at coulomb.eng.ohio-state.edu
Subject:	RE: Humidity

>Water, used in more than a modest amount, has the unfortunate tendency to
>absorb more heat from the combustion process than it returns in increased
>expansion of the working gasses.  This means that except for countering other
>bad things, water generally does no good.  The increased humidity - increased
>power effect most people observe is probably the reduced temperature induced
>air density increase. For most engines the pressure should peak about 15
>degrees and by about 20 after top dead center the fire is out.  The only hope
>for "free" energy that I can see is to inject water a la diesel directly into

I really didn't want to get into this postulation session, but
I'll bet any motorcycle rider out there will tell you that you
**definitely** have more power on hoomid days -- and it doesn't
matter what the temp !!  I think the reason it's more obvious on
the motorcycle is it's fewer cylinders -- dunno.

I think this apparent power increase is due to humidity -- not
water ..... now I really do know that humidity and water are the
same things but I believe that 70% RH is probably a lot different
than injecting water into the combustion chamber .... i.e. we've
gotten way off what was originally asked .... so, I'd still like
to know why I have more power when it's humid ??  (yeah, I know,
it's my i-magic-nation   8^)

Tom Cloud